Main article: Viewing system.
“The viewfinder is an essential part of most cameras for previewing what might be the image after...Viewfinder
“A Pentaprism is a five-sided optical glass element that reflects light through 90°. A variant...Pentaprism
“An instant-return mirror is a mirror in the reflex viewfinder of an SLR that automatically...Instant-return mirror
“Some cameras have no viewfinder per-se, but instead use a piece of ground glass at the focal...Ground glass back
“A reflex finder is a viewfinder system with a mirror placed behind a lens. The light passing...Reflex finder
“When you are taking a picture, you want to know with enough precision what will appear. This is...Viewing system